Oral immunogenicity of tomato-derived sDPT polypeptide containing Corynebacterium diphtheriae, Bordetella pertussis and Clostridium tetani exotoxin epitopes

Abstract

DPT vaccine, designed to immunize against diphtheria, pertussis, and tetanus, has been shown to be effective in humans. Nevertheless, dissatisfaction with the whole-cell preparations is due to the reactogenicity, which has to lead to the development of new safer formulations. Previously, we described the expression in tomato of a plant-optimized synthetic gene encoding the recombinant polypeptide sDPT, containing mainly immunoprotective epitopes of the diphtheria, pertussis and tetanus exotoxins and two adjuvants. In this study, we examined whether the ingestion of tomato-derived sDPT protein induces specific antibodies in mice after three weekly doses scheme. A positive group immunized with DPT toxoids was included. Specific antibody levels were assessed in serum, gut and lung. Sera tested for IgG antibody response to pertussis, tetanus and diphtheria toxin showed responses to the foreign antigens; interestingly, the response to diphtheria epitope was similar to those observed in the positive group. We found higher IgG1 than IgG2a responses in serum. A modest IgG response was observed in the tracheopulmonary fluid. High response of IgA against tetanus toxin was evident in gut, which was statistically comparable to that obtained in the positive group. The levels of response in these groups were higher than those in mice that received wild-type tomato. These findings support the concept of using transgenic tomatoes expressing sDPT polypeptide as model for edible vaccine against diphtheria, pertussis, and tetanus.

Tomato (Solanum lycopersicum L.) in the service of biotechnology

“…In 2007, Soria-Guerra et al obtained transgenic tomato plants (cv AC) expressing a synthetic gene encoding a novel synthetic recombinant polypeptide, sDTP (DiphtheriaPertussis-Tetanus) containing two adjuvant and six DPT immunoprotective exotoxin epitopes. In the course of subsequent studies, Soria-Guerra et al (2011) examined whether the ingestion of tomato-derived sDPT protein induced specific antibodies in mice. The results showed that the sera of the immunized mice tested for IgG antibodies, the response to pertussis, tetanus and diphtheria toxin, and showed responses to the foreign antigens.…”

Genetic Transformation in Tomato: Novel Tools to Improve Fruit Quality and Pharmaceutical Production

“…Recently, the same group examined whether immunization of mice fed with freeze-dried tomato material elicited specific antibody responses. Sera of immunized mice tested for IgG antibody response to pertussis, tetanus and diphtheria toxin showed responses to the foreign antigens; in addition, high response of IgA against tetanus toxin was evident in gut (Soria-Guerra et al, 2011). In addition, several studies investigated the feasibility of production of a safe, inexpensive plant-based mucosal vaccine against cholera.…”

“…Freeze-dried plant material could be stored for long time and consumed without cooking; in addition, this technique could allow to standardize and concentrate the plant-made vaccine. Several studies applied this technique to vaccine produced in transgenic tomato and demonstrated that freeze-dried produced stable formulations for oral delivery (Alvarez et al, 2006;Salyaev et al, 2010;Shchelkunov et al, 2006;Soria-Guerra et al, 2011;Zhang et al, 2006).…”

“…The production of plant-made mucosal vaccines eliminates needle-associated risks and downstream processing of traditional vaccines such as purification, sterilization and refrigeration. Recently, in addition to other systems, tomato plants have been used as vehicles for the expression and oral delivery of vaccines since tomato is edible, generates abundant biomass at low cost, has flexible growth conditions and contains the natural adjuvant -tomatine (Salyaev et al, 2010;Soria-Guerra et al, 2011). In this regards, it is noteworthy the work from Zhang and colleagues (2006) that expressed the recombinant Norwalk virus capsid protein in tomato and potato and demonstrated that, although in mice oral immunization with both dried tomato fruit and potato tuber elicited systemic and mucosal antibody responses, the recombinant vaccine in transgenic tomato fruit, especially in air-dried material, was a more potent oral immunogen than potato.…”

Plant biotechnology in support of the Millennium Goals

“…These are the subject of the article by Zhang et al (2011) which focuses on the example of tomato, while Sato et al (2011) address the problem of chilling tolerance in rice. The problem of expressing pharmacologically active peptides in plants is addressed in the study by Luchakivskaya et al (2011) and Soria-Guerra et al (2011). Finally, Subramanyam et al (2011) and Basnayake et al (2011) present progress towards the transformation of banana and diverse sugarcane cultivars, respectively.…”